An embedded direct-write 3D printing preparation method

Abstract

The present application relates to steel fiber ceramic composite material preparation technical field, specifically to a kind of steel fiber ceramic composite material's embedded direct writing 3D printing preparation method, comprising the following steps: S1, preparation ceramic matrix suspension and steel fiber ink;S2, embedded direct writing 3D printing is carried out;S3, to the part that printing is finished is dried, defatting and sintering.The method of the present application is low cost, fast, simple processing, without clean room environment, and the steel fiber ceramic composite material prepared has high precision and good practicability.

Description

[0001] This case is a divisional application based on the invention patent filed on 2022-11-09, with application number 202211397118.3 and titled "A Method for Preparing Embedded Direct-Write 3D Printing of Steel Fiber Ceramic Composite Material". Technical Field

[0002] This invention relates to the field of steel fiber ceramic composite material preparation technology, specifically to an embedded direct-write 3D printing preparation method. Background Technology

[0003] Ceramic materials possess advantages such as high strength, high hardness, good thermal stability, and oxidation resistance, making them the preferred material for applications involving exposure to harsh environments. However, ceramic materials suffer from drawbacks such as low fracture energy and brittleness. To improve the fracture energy of ceramic materials, a common approach is to fill the ceramic matrix with steel fiber fillers to prepare steel fiber ceramic composites.

[0004] However, existing methods for preparing steel fiber ceramic composites directly mix steel fibers with ceramic slurry, such as the Chinese invention patent application with application number 202110862623.X entitled "A non-fired high-strength metal-ceramic composite material and its preparation method and application". These methods cannot design the orientation of the steel fibers, and therefore cannot design the steel fiber structure to improve the fracture energy of the composite material by optimizing the steel fiber structure design, thus limiting the potential of steel fiber ceramic composite materials. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a low-cost and high-precision embedded direct-write 3D printing preparation method.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a method for preparing embedded direct-write 3D printing of steel fiber ceramic composite materials, comprising the following steps:

[0007] S1. Preparation of ceramic matrix suspension and steel fiber ink;

[0008] S2. Perform embedded direct-write 3D printing;

[0009] S3. Dry, degrease, and sinter the printed parts.

[0010] Further, S1 specifically includes step S11:

[0011] Thermosensitive hydrogel powder was dissolved in distilled water at mass percentages of 25 wt% and 30 wt%, respectively, and stored at 0–4°C for 24–36 hours to obtain two Pluronic gels with mass percentages of 25 wt% and 30 wt%, respectively.

[0012] Further, step S1 specifically includes step S12:

[0013] Alumina powder and 25 wt% Pluronic gel were mixed at a weight ratio of 7:3. Then, 1-3% of a dispersant by weight of alumina powder was added to obtain a mixture. The mixture was then placed in an ice bath and cooled for 20-30 minutes.

[0014] Further, S1 specifically includes step S13:

[0015] The cooled mixture was stirred at 2000 rpm to 2500 rpm for 5 to 10 minutes, and then placed in an ice bath to cool for 20 to 30 minutes. The stirring and cooling process was repeated 3 to 5 times to obtain a ceramic matrix suspension.

[0016] Further, step S1 specifically includes step S14:

[0017] Steel powder and 30 wt% Pluronic gel were mixed at a volume ratio of 1:3. Then, 0.5 to 1.5% of dispersant by weight of steel powder was added to obtain a mixture. The mixture was then placed in an ice bath and cooled for 20 to 30 minutes.

[0018] Further, S1 specifically includes step S15:

[0019] The cooled mixture is stirred at a speed of 2000 rpm to 2500 rpm for 5 to 10 minutes, and then placed in an ice bath to cool for 20 to 30 minutes. After repeating the stirring and cooling process 3 to 5 times, steel fiber ink is obtained.

[0020] Further, S2 specifically includes step S21:

[0021] The ceramic matrix suspension and the steel fiber ink were dried in a vacuum environment for 60-70 minutes.

[0022] Further, S2 specifically includes step S22:

[0023] The dried ceramic matrix suspension is cooled to 0-10°C and then poured into a silicone mold coated with silicone oil.

[0024] Furthermore, step S2 specifically includes step S23:

[0025] Place the silicone mold in a water bath at a temperature of 15-20℃, inject steel fiber ink into a syringe for direct writing 3D printing, and extrude ink filaments with a diameter of 10-700um through a nozzle with an inner diameter of 10-600um.

[0026] Furthermore, step S3 specifically includes the following steps:

[0027] S31. Remove the silicone mold containing the ceramic matrix suspension and printing ink, and dry it in an environment at 32°C for 1 to 2 weeks.

[0028] S32. Remove the dried ceramic matrix suspension from the silicone mold and place it in a sintering furnace. Increase the temperature from room temperature to 350°C at a rate of 1°C / min and hold for 1-2 hours. Then, continue to increase the temperature to 500°C at a rate of 2°C / min and hold for 2-3 hours. Then, open the furnace and cool down to room temperature.

[0029] S33. Heat the temperature from room temperature to 1550℃ at a heating rate of 5℃ / minute and keep it at that temperature for 2-3 hours. Finally, open the box and cool it down to room temperature.

[0030] The beneficial effects of this invention are as follows: This invention overcomes the problem that existing methods for preparing steel fiber ceramic composites directly mix steel fibers with ceramic slurry, making it impossible to design the orientation of the steel fibers. Therefore, it is impossible to design the steel fiber structure to improve the fracture energy of the composite material through optimization of the steel fiber structure, thus limiting the potential of steel fiber ceramic composites. This invention proposes an embedded direct-write 3D printing method for preparing steel fiber ceramic composites. This method, based on embedded direct-write 3D printing technology, prepares a self-healing ceramic gel. This gel allows the direct-write 3D printing nozzle to move inside it and heals without defects after the nozzle passes through. Simultaneously, steel fiber ink is printed within the ceramic gel using direct-write 3D printing. In subsequent heat treatment, the gel forms a dense, defect-free ceramic that encapsulates the steel fiber ink. Finally, sintering solidifies the steel fiber ink and ceramic gel to prepare a steel fiber ceramic composite material with a designable steel fiber structure. The method of this invention is low-cost, fast, simple to process, requires no cleanroom environment, and produces steel fiber ceramic composite materials with high precision and excellent practicality. Attached Figure Description

[0031] Figure 1 This is a schematic flowchart of the embedded direct-write 3D printing preparation method of the steel fiber ceramic composite material of the present invention;

[0032] Figure 2 This is a schematic diagram of the printer settings for embedded direct-write 3D printing in step S2 of this embodiment of the invention;

[0033] Figure 3 This is a schematic diagram of steel fiber ink extrusion in step S2 of the embodiment of the present invention for embedded direct-write 3D printing;

[0034] Label Explanation:

[0035] 1. Piston; 2. Syringe; 3. Nozzle; 4. Silicone mold; 5. Water bath; 6. Ceramic matrix suspension; 7. Steel fiber ink. Detailed Implementation

[0036] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0037] Direct-write 3D printing, a type of extrusion 3D printing within additive manufacturing, holds great promise for applications in ceramic material preparation. This technology involves continuously extruding ceramic slurry to prepare ceramic preforms, which are then dried, degreased, and sintered to ultimately produce dense ceramic parts. Embedded direct-write 3D printing is an emerging variant of direct-write 3D printing. It is based on printing complex structures within a soft support matrix, offering superior manufacturing freedom and enabling the fabrication of complex micro-scale structures. Therefore, this invention proposes a method for preparing steel fiber ceramic composites using embedded direct-write 3D printing, enabling the printing of complex, designable steel fiber structures within dense ceramic structures.

[0038] Please refer to Figures 1 to 3 An embedded direct-write 3D printing method for steel fiber ceramic composite materials includes the following steps:

[0039] S1. Prepare ceramic matrix suspension 6 and steel fiber ink 7;

[0040] S2. Perform embedded direct-write 3D printing;

[0041] S3. Dry, degrease, and sinter the printed parts.

[0042] As described above, the beneficial effects of this invention are as follows: This invention overcomes the problem that existing methods for preparing steel fiber ceramic composites directly mix steel fibers with ceramic slurry, making it impossible to design the orientation of the steel fibers. Therefore, it is impossible to design the steel fiber structure to improve the fracture energy of the composite material through optimized steel fiber structure design, thus limiting the potential of steel fiber ceramic composites. This invention proposes an embedded direct-write 3D printing method for preparing steel fiber ceramic composites. This method, based on embedded direct-write 3D printing technology, prepares a self-healing ceramic gel. This gel allows the direct-write 3D printing nozzle to move inside it and heals without defects after the nozzle passes through. Simultaneously, steel fiber ink is printed within the ceramic gel using direct-write 3D printing. In subsequent heat treatment, the gel forms a dense, defect-free ceramic that encapsulates the steel fiber ink. Finally, sintering solidifies the steel fiber ink and ceramic gel to prepare a steel fiber ceramic composite material with a designable steel fiber structure. The method of this invention is low-cost, fast, simple to process, requires no cleanroom environment, and produces steel fiber ceramic composite materials with high precision and excellent practicality.

[0043] In an optional embodiment, S1 specifically includes step S11:

[0044] Thermosensitive hydrogel powder was dissolved in distilled water at mass percentages of 25 wt% and 30 wt%, respectively, and stored at 0–4°C for 24–36 hours to obtain two Pluronic gels with mass percentages of 25 wt% and 30 wt%, respectively.

[0045] As described above, Pluronic is a thermosensitive hydrogel composed of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO). Pluronic powder was dissolved in distilled water at mass percentages of 25 wt% and 30 wt%, respectively, and stored in a refrigerator at 0-4°C for 24-36 hours to obtain two Pluronic gels with mass percentages of 25 wt% and 30 wt%, respectively.

[0046] Preferably, the grade of Pluronic powder is: Pluronic F127.

[0047] In an optional embodiment, S1 specifically includes step S12:

[0048] Alumina powder and 25 wt% Pluronic gel were mixed at a weight ratio of 7:3. Then, 1-3% of a dispersant by weight of alumina powder was added to obtain a mixture. The mixture was then placed in an ice bath and cooled for 20-30 minutes.

[0049] In an optional embodiment, S1 specifically includes step S13:

[0050] The cooled mixture was stirred at 2000 rpm to 2500 rpm for 5 to 10 minutes, and then placed in an ice bath to cool for 20 to 30 minutes. After repeating the stirring and cooling process 3 to 5 times, a ceramic matrix suspension 6 was obtained.

[0051] As described above, alumina powder is added to 25 wt% Pluronic gel at a weight ratio of 7:3, and a dispersant of 1-3% of the alumina powder mass is added. The mixture is cooled in an ice bath for 20-30 minutes. After cooling, the mixture is stirred in a stirrer at a speed of 2000-2500 rpm for 5-10 minutes. Then, it is cooled in an ice bath for 20-30 minutes. The mixing and cooling steps are repeated 3-5 times to obtain a ceramic matrix suspension 6.

[0052] Preferably, the brand name of the dispersant is Dolapix CA.

[0053] Preferably, the purpose of performing multiple mixing and cooling steps is to thoroughly mix the powder to obtain a uniform, clump-free ceramic matrix suspension 6.

[0054] In an optional embodiment, S1 specifically includes step S14:

[0055] Steel powder and 30 wt% Pluronic gel were mixed at a volume ratio of 1:3. Then, 0.5 to 1.5% of dispersant by weight of steel powder was added to obtain a mixture. The mixture was then placed in an ice bath and cooled for 20 to 30 minutes.

[0056] In an optional embodiment, S1 specifically includes step S15:

[0057] The cooled mixture is stirred at a speed of 2000 rpm to 2500 rpm for 5 to 10 minutes, and then placed in an ice bath to cool for 20 to 30 minutes. After repeating the stirring and cooling process 3 to 5 times, steel fiber ink 7 is obtained.

[0058] As described above, steel powder and 30 wt% Pluronic gel prepared in step S101 are mixed at a volume ratio of 1:3. 0.5-1.5% of a dispersant based on the mass of the steel powder is added. The mixture is cooled in an ice bath for 20-30 minutes. After cooling, the mixture is stirred in a stirrer at a speed of 2000-2500 rpm for 5-10 minutes. Then, it is cooled in an ice bath for another 20-30 minutes. The mixing and cooling steps are repeated 3-5 times to obtain steel fiber ink 7.

[0059] Preferably, the particle size of the steel powder is 5–8 μm.

[0060] Preferably, the brand name of the dispersant is Dolapix CA.

[0061] Preferably, the purpose of performing multiple mixing and cooling steps is to thoroughly mix the powder to obtain a uniform steel fiber ink 7.

[0062] In an optional embodiment, S2 specifically includes step S21:

[0063] The ceramic matrix suspension 6 and the steel fiber ink 7 were dried in a vacuum environment for 60-70 minutes.

[0064] As described above, the above steps are used to eliminate air bubbles in the ceramic matrix suspension 6 and the steel fiber ink 7.

[0065] In an optional embodiment, S2 specifically includes step S22:

[0066] The dried ceramic matrix suspension 6 is cooled to 0-10°C and then poured into a silicone mold 4 coated with silicone oil.

[0067] As can be seen from the above description, the purpose of cooling the ceramic matrix suspension 6 to 0-10℃ is to ensure that the viscosity of the ceramic matrix suspension 6 is low at 0-10℃, making it easier to fill the silicone mold 4.

[0068] Preferably, the silicone mold 4 is a rectangular container with an opening at the top, and the material is silicone.

[0069] Preferably, the silicone mold 4 is coated with silicone oil to facilitate demolding.

[0070] In an optional embodiment, a 3D model of the flow channel to be printed is constructed in 3D modeling software, the 3D model is saved as an STL file and imported into slicing software, printing parameters are set in slicing software, a G-code file is generated, and the G-code file is imported into a direct-write 3D printer for embedded direct-write 3D printing.

[0071] In an optional embodiment, S2 specifically includes step S23:

[0072] Place the silicone mold 4 in a water bath 5 at a temperature of 15-20℃, inject the steel fiber ink 7 into the syringe 2 for direct writing 3D printing, the syringe 2 has a piston 1, and extrude ink filaments with a diameter of 10-700um through the nozzle 3 with an inner diameter of 10-600um.

[0073] As described above, during the printing process, the silicone mold 4 is placed in a water bath 5 at a temperature of 15-20℃ to ensure that the temperature of the ceramic matrix suspension 6 in the silicone mold 4 is 15-20℃, so that the ceramic matrix suspension 6 has sufficient viscosity to support the printing ink.

[0074] Preferably, during the printing process, the nozzle 3 is in the ceramic matrix suspension 6, and the ink is extruded as filaments suspended in the ceramic matrix suspension 6.

[0075] In an optional embodiment, step S3 specifically includes the following steps:

[0076] S31. Drying: Remove the silicone mold 4 containing the ceramic matrix suspension 6 and the printing ink, and place it in an environment with a temperature of 32°C to dry for 1 to 2 weeks.

[0077] S32, Degreasing: Take the dried ceramic matrix suspension 6 out of the silicone mold 4 and place it in the sintering furnace. Raise the temperature from room temperature to 350°C at a rate of 1°C / min and hold for 1-2 hours. Then raise the temperature to 500°C at a rate of 2°C / min and hold for 2-3 hours. Then open the furnace and cool down to room temperature.

[0078] S33, Sintering: Raise the temperature from room temperature to 1550℃ at a heating rate of 5℃ / minute and hold for 2-3 hours. Finally, open the oven and cool down to room temperature.

[0079] As described above, through drying, degreasing, and sintering, the ceramic matrix suspension becomes a dense ceramic part, while the steel fiber ink solidifies during the sintering process, ultimately forming a high-precision, designable, and complex steel fiber structure in the ceramic part, thus completing the preparation of the steel fiber ceramic composite material.

[0080] Please refer to Figures 1 to 3 Embodiment 1 of the present invention is: a method for preparing embedded direct-write 3D printing of steel fiber ceramic composite materials:

[0081] S1. Prepare ceramic matrix suspension 6 and steel fiber ink 7;

[0082] S2. Perform embedded direct-write 3D printing;

[0083] S3. Dry, degrease, and sinter the printed parts.

[0084] Furthermore, the specific operation of step S1 is as follows:

[0085] S101. Pluronic (a thermosensitive hydrogel composed of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO)) powder and distilled water were dissolved in distilled water at a mass percentage of 25 wt% and 30 wt%, respectively, and stored in a refrigerator at 0-4°C for 24-36 hours to obtain two Pluronic gels with mass percentages of 25 wt% and 30 wt%, respectively.

[0086] S102. Add alumina powder to the 25wt% Pluronic gel prepared in step S101 at a weight ratio of 7:3, add 1-3% of the alumina powder mass as a dispersant, cool the mixture in an ice bath for 20-30 minutes, stir the cooled mixture in a stirrer at a speed of 2000-2500 rpm for 5-10 minutes, and then cool it in an ice bath for 20-30 minutes. Repeat the mixing and cooling steps 3-5 times to obtain a ceramic matrix suspension 6.

[0087] S103. Mix steel powder with 30 wt% Pluronic gel prepared in step S101 at a volume ratio of 1:3. Add 0.5-1.5% of dispersant by weight of steel powder. Cool the mixture in an ice bath for 20-30 minutes. After cooling, stir the mixture in a stirrer at a speed of 2000 rpm-2500 rpm for 5-10 minutes. Then cool it in an ice bath for 20-30 minutes. Repeat the mixing and cooling steps 3-5 times to obtain steel fiber ink 7.

[0088] The specific operation of step S2 is as follows:

[0089] S201. Place the ceramic matrix suspension 6 prepared in step S102 and the steel fiber ink 7 prepared in step S103 into a vacuum dryer and dry for 60-70 minutes to eliminate air bubbles in the ceramic matrix suspension 6 and the steel fiber ink 7.

[0090] S202. Cool the ceramic matrix suspension 6 obtained in step 201 to 0-10℃ and pour it into the silicone mold 4 coated with silicone oil.

[0091] S203. Inject the steel fiber ink 7 obtained in step 201 into the syringe 2 for direct writing 3D printing;

[0092] S204. Construct a 3D model of the flow channel to be printed in the 3D modeling software. Save the 3D model as an STL file and import it into the slicing software. Set the printing parameters in the slicing software and generate a G-code file. Import the G-code file into the direct-write 3D printer for embedded direct-write 3D printing.

[0093] The specific operation of step S3 is as follows:

[0094] S301. Drying: After printing, remove the silicone mold 4 containing the ceramic matrix suspension 6 and the printed ink, and place it in a convection oven. The humidity in the oven is set to 72±3% by placing a supersaturated sodium chloride solution in the oven, the oven temperature is set to 32℃, and a fan is placed in the oven to promote air circulation. The drying time is 1-2 weeks.

[0095] S302, Degreasing: Take the dried ceramic matrix suspension 6 from the silicone mold 4 in step S301 and place it in the sintering furnace. In order to ensure that the parts do not crack during the sintering process, degreasing is required before sintering. The specific operation is as follows: the heating rate is 1℃ / min, the temperature is raised from room temperature to 350℃ and held for 1-2 hours, the temperature is raised at a heating rate of 2℃ / min to reach 500℃, and after reaching 500℃, it is held for 2-3 hours and then the furnace is opened and cooled to room temperature.

[0096] S303, Sintering: Sintering is carried out after degreasing. The specific operation is as follows: the temperature is raised from room temperature to 1550℃ at a heating rate of 5℃ / minute. After reaching 1550℃, the temperature is held for 2-3 hours and then the box is opened to cool down to room temperature.

[0097] In summary, this invention overcomes the limitations of existing steel fiber ceramic composite material preparation methods, which directly mix steel fibers with ceramic slurry, making it impossible to design the orientation of the steel fibers. This prevents the design of steel fiber structures to improve the fracture energy of the composite material, thus restricting its potential. This invention proposes an embedded direct-write 3D printing method for preparing steel fiber ceramic composite materials. Based on embedded direct-write 3D printing technology, this method prepares a self-healing ceramic gel. This gel allows the direct-write 3D printing nozzle to move within it and heals without defects after the nozzle passes through. Simultaneously, steel fiber ink is printed within the ceramic gel using direct-write 3D printing. During subsequent heat treatment, the gel forms a dense, defect-free ceramic that encapsulates the steel fiber ink. Finally, sintering solidifies the steel fiber ink and ceramic gel to prepare a steel fiber ceramic composite material with a designable steel fiber structure. This invention's method is low-cost, fast, simple to process, requires no cleanroom environment, and produces high-precision steel fiber ceramic composite materials with excellent practicality.

[0098] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An embedded direct-write 3D printing fabrication method, characterized in that, Includes the following steps: S1. Dissolve the powder of a thermosensitive hydrogel composed of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) in distilled water at mass percentages of 25 wt% and 30 wt%, respectively, and store them at 0-4°C for 24-36 hours to obtain two Pluronic gels with mass percentages of 25 wt% and 30 wt%, respectively. Mix alumina powder with 25 wt% Pluronic gel at a weight ratio of 7:3, and then add 1-3% of a dispersant by mass of alumina powder to obtain a mixture. Cool the mixture in an ice bath for 20-30 minutes. Stir the cooled mixture at 2000 rpm to 2500 rpm for 5-10 minutes, and then cool it in an ice bath for 20-30 minutes. Repeat the stirring and cooling process 3-5 times to obtain a uniform, clump-free ceramic matrix suspension. Steel powder and 30 wt% Pluronic gel were mixed at a volume ratio of 1:

3. Then, 0.5-1.5% of dispersant by weight of steel powder was added to obtain a mixture. The mixture was placed in an ice bath and cooled for 20-30 minutes. The cooled mixture was stirred at 2000-2500 rpm for 5-10 minutes and then placed in an ice bath and cooled for 20-30 minutes. The stirring and cooling process was repeated 3-5 times to obtain a uniform steel fiber ink. S2. Perform embedded direct-write 3D printing: S2 specifically includes step S21: The ceramic matrix suspension and the steel fiber ink were dried in a vacuum environment for 60-70 minutes respectively. S2 specifically includes step S22: The dried ceramic matrix suspension is cooled to 0~10℃ and then poured into a silicone mold coated with silicone oil. S2 specifically includes step S23: Place the silicone mold in a water bath at a temperature of 15-20℃ to maintain the temperature of the ceramic matrix suspension in the silicone mold at 15-20℃. Inject steel fiber ink into a syringe for direct writing 3D printing. Construct a 3D model of the flow channel to be printed in 3D modeling software. Save the 3D model as an STL file and import it into slicing software. Set the printing parameters in the slicing software and generate a G-code file. Import the G-code file into the direct writing 3D printer for embedded direct writing 3D printing. The nozzle is in the ceramic matrix suspension, and the ink is extruded into filaments suspended in the ceramic matrix suspension. The nozzle with an inner diameter of 10-600μm extrudes ink filaments with a diameter of 10-700μm. S3. Dry, degrease and sinter the printed parts; S3 specifically includes the following steps: S31. Remove the silicone mold containing the ceramic matrix suspension and printing ink, place a fan and a 72±3% supersaturated sodium chloride solution in a convection oven, and dry it in a convection oven at a temperature of 32℃ for 1-2 weeks. S32. Remove the dried ceramic matrix suspension from the silicone mold and place it in a sintering furnace. Increase the temperature from room temperature to 350°C at a rate of 1°C / min and hold for 1-2 hours. Then, continue to increase the temperature to 500°C at a rate of 2°C / min and hold for 2-3 hours. Then, open the furnace and cool to room temperature. S33. Heat the temperature from room temperature to 1550℃ at a heating rate of 5℃ / minute and keep it at that temperature for 2-3 hours. Finally, open the box and cool it down to room temperature.

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